1. Field of the Invention
The present invention relates to an organophosphorus compound represented by the following general formula (I): ##STR3## [wherein R.sup.1 and R.sup.2 each represents a C.sub.1 to C.sub.4 alkyl group; X represents O, S, CH.sub.2, CH--R.sup.3 (wherein R.sup.3 represents a C.sub.1 to C.sub.3 alkyl group), NH or N--R.sup.4 {wherein R.sup.4 represents a C.sub.1 to C.sub.4 alkyl group (the alkyl group may be substituted with at least one group selected from the group consisting of alkoxy, alkylthio, cyano, alkoxyalkyloxy and alkylamino groups and halogen atoms), an alkenyl group which may be substituted with halogen atoms, an alkynyl group which may be substituted with halogen atoms, a phosphoric acid ester radical, a cyano group, a group of the following general formula (II): ##STR4## (wherein R.sup.5 represents an alkyl or alkylamino group which may be substituted with halogen atoms) or a group represented by the following general formula: --(R.sup.6).sub.n --CO--R.sup.7 (wherein n is 0 or 1; R.sup.6 represents a methylene group which may be substituted with alkyl groups, or an ethylene group which may be substituted with alkyl groups; R.sup.7 represents an alkyl group which may be substituted with halogen atoms, an alkoxy group which may be substituted with halogen atoms, an alkylthio group, an alkylamino group or a hydrogen atom)}; Z represents a group represented by the general formula: N--R.sup.8 (R.sup.8 represents a nitro group, a cyano group, an alkylsulfonyl group which may be substituted with halogen atoms, a tosyl group or an alkylcarbonyl group which may be substituted with halogen atoms) or a group represented by the general formula: C(CN)R.sup.9 (wherein R.sup.9 represents a cyano group or an alkoxycarbonyl group); and A represents an ethylene group which may be substituted with C.sub.1 to C.sub.3 alkyl groups, a trimethylene group which may be substituted with C.sub.1 to C.sub.3 alkyl groups or a group represented by the general formula: --CH.sub.2 NR.sup.10 CH.sub.2 -- (wherein R.sup.10 is a C.sub.1 to C.sub.3 alkyl group)]. The compound of formula (I) according to the present invention specifically excludes an organophosphorus compound of the general formula (I) in which R.sup.1 and R.sup.2 are C.sub.1 to C.sub.4 alkyl groups respectively, X is NH, Z is a cyanoimino group or a nitroimino group and A is an ethylene group which may be substituted with C.sub.1 to C.sub.3 alkyl groups or a trimethylene group which may be substituted with C.sub.1 to C.sub.3 alkyl groups. The present invention also relates to a method for preparing the compound, of formula (I), and insecticides, acaricides and nematocides which comprise the compound as an active ingredient.
2. Prior Art Statement
Recently, organophosphorus compounds having an imidazolidinyl group have been investigated and developed. For instance, Japanese Unexamined Patent Publication No. Sho 61-267594 and Japanese Unexamined Patent Publication No. Hei 2-793 disclose that these compounds can be used as insecticides, acaricides, nematocides and agents for killing soil insect pests. However, these patents simply disclose organophosphorus compounds having an imidazolidine skeleton which carries an oxygen or sulfur atom on the 2-position. Moreover, the insecticidal, acaricidal and nematocidal effects of these compounds are insufficient and are not necessarily satisfactory.